Manufacturing method of a suspension

ABSTRACT

A suspension includes a resilient flexure for supporting a magnetic head slider near its one end, and a load beam with a base end portion, for supporting the flexure. Particularly, connection conductors are formed on the flexure in a thin film pattern, and one ends of the connection conductors are to be connected to the magnetic head slider and the other ends of the connection conductors are positioned near the other end of the flexure. The other end of the flexure extends to at least a position of the base end portion of the load beam.

This application is a divisional application of Ser. No. 08/736,436 U.S.Pat. No. 5,754,368, filed Oct. 24, 1996.

FIELD OF THE INVENTION

The present invention relates to a suspension, a slider-suspensionassembly, an assembly carriage device and a method of manufacturing thesuspension, used in a magnetic disk drive apparatus or a photo-magneticdisk drive apparatus wherein a magnetic head slider opposes to thesurface of a rotating magnetic or photo-magnetic disk with a very lowflying height so as to read and write information from and into thedisk.

DESCRIPTION OF THE RELATED ART

The suspension supports a magnetic head slider near its one end andapplies a pressure force against the slider toward the disk surface.This pressure force is compensated by the force of the air-bearingbetween an air-bearing surface of the slider and the rotating disksurface. Thus, the slider can be moved on the rotating disk surface withkeeping a small space between them so as to read and write informationfrom and into the disk.

U.S. Pat. No. 4,167,765 of Watrous discloses a typical suspensionstructure with a load beam mounted at one end to a rigid actuator arm,and a flexure element which is attached to the other end of the loadbeam and support a magnetic head slider. The load beam provides theresilient spring action for biasing the slider toward the disk surface,while the flexure element provides flexibility for the slider as theslider rides on the cushion of air between the air-bearing surface andthe rotating disk surface. Suspensions with such structure arecommercially supplied as type T-8 or T-19 suspensions from HutchinsonTechnology Inc. and widely utilized in this field.

In general, the magnetic head slider is supported by the flexure part ofthe suspension having the above-mentioned structure and a plurality ofwires are provided for lead lines of the magnetic head slider. Namely,one end of each of the wires is electrically connected to each signalterminal of the magnetic head slider, whereas the other end of the eachwire is electrically connected to a cable terminal formed at one end ofa flexible printed circuit (FPC) which is connected at the other endthereof to an integrated circuit element for recording and reproducingsignals mounted in the magnetic or photo-magnetic disk drive apparatus.

Recent requirement for higher magnetic recording density has promoted anextremely lower flying height of the magnetic slider such as 0.1 μm orless and a lower size of the slider itself as well as a lower resilientpressure force against the slider toward the disk surface.

For such downsized magnetic head slider, rigidity of the lead wires willgreatly exert a bad influence upon the flying characteristics of theslider. Particularly, motion for roll of the slider is severely affectedby the rigidity of these wires. In addition, downsizing of the sliderwill invite great difficulty of connection work of the wires with thesignal input/output terminals of the slider. Using of the lead wiresalso requires additional works for connecting the other end of the wireswith a plurality of cable terminals formed on the FPC. Since thisconnection work has to be executed by hand, one by one, the operationefficiency of manufacturing the slider-suspension assembly will beextremely lowered. In addition, it requires skill for the workers.

Suspensions with improved structure which can solve the above-mentionedproblems of the typical suspension are described in Japanese PatentUnexamined Publication Nos. 4(1992)-40680 and 5(1993)-282642. In each ofthese known suspensions, a thin film conductive pattern as for leadlines is formed on the flexure which is supported by the load beam atits one end, and one ends of the lead lines of the conductive patternare connected directly with signal terminals of the magnetic head slidermounted on the flexure. Thus, according to these improved suspensions,complicated connection work of the wires with the slider due todownsizing of the slider can be avoided, and also the flying heightchange as well as low durability of the device due to the rigidity ofthe wires can be prevented.

However, in these known suspensions, the flexure with the thin filmconductive pattern as for lead lines is partially formed only a smallregion near the top end of the load beam, at which the slider ismounted, and therefore wires have to be likewise used for electricallyconnecting the other ends of the lead lines of the conductive patternwith an external circuit (one end of the FPC). Thus, following problemswill be occurred.

If the wires with a large diameter are used for the connection with theexternal circuit to decrease their electrical resistance, the rigidityof these wires greatly exert a bad influence upon the flyingcharacteristics of the downsized slider. Contrary to this, if the wireswith a small diameter are used, the electrical resistance will extremelyincrease and also breakage of the wires may easily occur at theconnection work causing fraction defective of manufacturing to increase.

Also, since it is necessary to carry out double connection works forconnecting the conductive pattern with one ends of the wires and forconnecting the other ends of the wires with the cable terminals at theone end of the FPC, the connection works become so much complicated.Furthermore, since these connection works have to be executed by hand,one by one, the operation efficiency of manufacturing theslider-suspension assembly becomes extremely low. In addition, itrequires skill for the workers. Because of connection with the wires,breakage may also easily occur at the connection works causing fractiondefective of manufacturing to increase. Particularly, if small diameterwires are used in order to decrease bad influence upon the flyingcharacteristics of the downsized slider, breakage of the wires will veryeasily occur at the connection works causing the fraction defective ofmanufacturing to greatly increase.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide asuspension, a slider-suspension assembly and an assembly carriagedevice, whereby connection of lead lines of a magnetic head slider willnot affect the flying characteristics of the slider, particularly motionof the slider for roll.

Another object of the present invention is to provide a suspension, aslider-suspension assembly and an assembly carriage device, whereby anelectrical resistance of lead lines to be connected with a magnetic headslider can be decreased.

Further object of the present invention is to provide a suspension, aslider-suspension assembly, an assembly carriage device and a method ofmanufacturing the suspension, whereby connection work between lead linesand an external circuit can be easily executed resulting themanufacturing cost with respect to the connection to reduce.

The present invention relates a suspension including a resilient flexurefor supporting a magnetic head slider near its one end, and a load beamwith a base end portion, for supporting the flexure. Particularly,according to the present invention, connection conductors are formed onthe flexure in a thin film pattern, and one ends of the connectionconductors are to be connected to the magnetic head slider and the otherends of the connection conductors are positioned near the other end ofthe flexure. The other end of the flexure extends to at least a positionof the base end portion of the load beam.

Also, the present invention relates a slider-suspension assemblyincluding a magnetic head slider, a resilient flexure for supporting themagnetic head slider near its one end, and a load beam with a base endportion, for supporting the flexure. Particularly, according to thepresent invention, connection conductors are formed on the flexure in athin film pattern, and one ends of the connection conductors areconnected to the magnetic head slider and the other ends of theconnection conductors are positioned near the other end of the flexure.The other end of the flexure extends to at least a position of the baseend portion of the load beam.

The connection conductors are formed on the flexure in a thin filmpattern. One ends of the connection conductors are electricallyconnected to the magnetic head slider and the other ends of theconnection conductors are positioned near the other end of the flexure.The other end of the flexure extends to at least a position of the baseend portion of the load beam. Thus, the other ends of the respectiveconnection conductors can be directly connected, without using leadwires, to cable terminals of the FPC connection cable. The other end ofthe connection cable is connected to an electronic circuit for recordingand reproducing signals. As a result, the connection of the lead lineswill not affect the flying characteristics of the slider, particularlymotion of the slider for roll, and an electrical resistance of the leadlines can be decreased. This is extremely advantageous for a magnetichead slider with a very small size, and also for a magnetic head sliderwith a large number of lead lines. Also, the connection work of the leadlines with the external circuit can be very easily executed and may beautomatically executed by a connection machine. As a result, themanufacturing cost with respect to the connection can be reduced.Furthermore, since the flexure is attached to the load beam along thewhole length of the load beam, a good damper effect can be expected.

It is preferred that the other end of the flexure is positioned at theside of the base end portion of the load beam or extends beyond the sideof the base end portion of the load beam.

It is also preferred that the other ends of the connection conductorsare connected to connection terminals positioned near the other end ofthe flexure, respectively.

The other end of the flexure may be fixed to the load beam or may befree from the load beam to form a free end.

Preferably, the magnetic head slider is a slider having at least foursignal terminals connected to the one ends of the connection conductors,respectively, and an air bearing surface with an area equal to or lessthan 2 mm².

According to the present invention, furthermore, the load beam mayinclude a terminal support part protruded from a side edge of the baseend portion of the load beam and bent to an arbitrary angle with respectto a surface of the base end portion. A first connection terminal partpositioned near the one end of the flexure and to be connected to themagnetic head slider, a second connection terminal part positioned nearthe other end of the flexure, and connection conductors with both endsconnected with the first and second connection terminal parts may beformed on the flexure in a thin film pattern. The other end of theflexure is fixed to the terminal support part so that the secondconnection terminal part is outward appeared with respect to the baseend portion at a position of the terminal support part.

The second connection terminal part of the thin film conductive patternformed on the flexure is positioned on the terminal support part byattaching the other end portion of the flexure to this terminal supportpart which is protruded from the base end portion of the load beam.Thus, the second connection terminal part can be directly connected,without using lead wires, to one end of a FPC connection cable, theother end of which is connected to an external circuit such as anelectronic circuit for recording and reproducing signals. As a result,the connection of the lead lines will not affect the flyingcharacteristics of the slider, particularly motion of the slider forroll, and an electrical resistance of the lead lines can be decreased.Also, any breakage of the wires can be prevented from occurring duringconnection works resulting the fraction defective of manufacturing tomaintain without increasing.

Furthermore, since the second connection terminal part is fixed to theterminal support part which is bent to an arbitrary angle with respectto the surface of the base end portion of the load beam, the connectionterminals are outward appeared resulting that the connection work withthe FPC can be easily done. Also, because the position of the connectionterminals is settled, the connection work of the lead lines with theexternal circuit can be automatically executed by a connection machine.As a result, the manufacturing cost with respect to the connection canbe reduced. Furthermore, since the flexure is attached to the load beamalong the whole length of the load beam, a good damper effect can beexpected.

It is preferred that the flexure includes a free movement part near theother end of the flexure, and that this free movement part is capable offreely moving with respect to the load beam. Therefore, even if theflexure is fixed at its the other end to the terminal support part ofthe load beam, the free movement part can freely move with respect tothe load beam without sharply bent. Thus, excess stress will not beapplied to the thin film conductive pattern on the flexure such as theconnection conductors. This can prevent the electrical characteristicssuch as electrical insulation or resistance of the conductive patternfrom deteriorating.

It is also preferred that the flexure includes a play to provide ananti-twist function in the free movement part. Thanks for the play, thefree movement part can more freely move. As a result, no excess stressis applied to the thin film conductive pattern on the flexure even if apart of the flexure is distorted during the bending. Therefore, it isvery advantageous for preventing the electrical characteristics fromdeteriorating.

In one embodiment of the present invention, the terminal support part issubstantially bent perpendicular to a surface of the base end portion ofthe load beam. However, this bending angle may be adaptively decided oncondition that the connection work with the external circuit can beeasily executed. Smaller bending angle is advantageous because theprotruding length of the terminal support part will be decreased.

Preferably, the load beam includes a slit along a line for bending theterminal support part. This partial formation of the slit along thebending line will provide no excess stress to the thin film conductivepattern on the flexure such as the connection conductors preventing theelectrical characteristics such as electrical insulation or electricalresistance characteristics from deteriorating. Of course, the bendingwork will become easy.

According to the present invention, furthermore, an assembly carriagedevice includes a carriage having a plurality of drive arms to which thebase end portions of the load beams in the above mentionedslider-suspension assemblies are respectively fixed, an actuator fordriving the carriage to rotate, and a connection cable of a flexibleprinted circuit connected at its one end to an external electricalcircuit for recording and reproducing signals. The connection cable hascable terminals connected respectively to the other ends of theconnection conductors at its the other end.

It is preferred that the flexure includes connection terminals connectedrespectively to the other ends of the connection conductors near theother end of the flexure. The connection terminals are connected to thecable terminals, respectively.

It is also preferred that the connection terminals and the other end ofthe flexure are positioned at the side of the base end portion of theload beam or extend beyond the side of the base end portion of the loadbeam.

According to the present invention also a method of manufacturing asuspension includes a step of forming a resilient flexure having a firstconnection terminal part positioned near one end of the flexure and tobe connected to a magnetic head slider, a second connection terminalpart positioned near the other end of the flexure, and connectionconductors with both ends connected with the first and second connectionterminal parts, in a thin film pattern, a step of forming a load beamhaving a base end portion and a terminal support part protruded from aside edge of the base end portion of the load beam, a step of attachingthe flexure on the load beam so that the second connection terminal partis fixed on the terminal support part, and a step of bending theterminal support part to an arbitrary angle with respect to a surface ofthe base end portion so that the second connection terminal part isoutward appeared with respect to the base end portion at a position ofthe terminal support part.

Since the terminal support part is bent after the fixing of the otherend of the flexure to this terminal support part of the load beam,bending work can be easily done and also the bending angle can beoptionally determined.

It is preferred that the load beam forming step includes a step offorming a slit along a line for bending the terminal support part. Thisslit will provides no excess stress to the thin film conductive patternon the flexure such as the connection conductors preventing theelectrical characteristics such as electrical insulation or electricalresistance characteristics from deteriorating, and also easy bendingwork.

Further objects and advantages of the present invention will be apparentfrom the following description of the preferred embodiments of theinvention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view schematically illustrating a part of amagnetic disk drive apparatus in a preferred embodiment according to thepresent invention;

FIG. 2 is a plane view of a suspension used in the embodiment shown inFIG. 1;

FIG. 3 is an oblique view illustrating an example of connectionstructure between connection terminals formed near the top end of aflexure of the suspension shown in FIG. 2 and signal terminals of amagnetic head slider;

FIG. 4 is a side view schematically illustrating an assembly carriagedevice used in the embodiment shown in FIG. 1;

FIG. 5 is a plane view of FPC of the magnetic disk drive apparatus shownin FIG. 1;

FIG. 6 is a side view schematically illustrating an example ofconnection structure between connection conductors of the flexure shownin FIG. 2 and a connection cable of the FPC;

FIG. 7 is a graph illustrating measured flying characteristics of aslider-suspension assembly used in the embodiment of FIG. 1 and of theconventional slider-suspension assembly using wires as for the leadlines;

FIG. 8 is a plane view of a suspension used in an another embodimentaccording to the present invention;

FIGS. 9a to 9c are sectional views along the A--A line shown in FIG. 8;

FIG. 10 is a plane view illustrating in detail a flexure used in theembodiment shown in FIG. 8;

FIG. 11 is a plane view illustrating a terminal support part of a loadbeam of the suspension shown in FIG. 8;

FIG. 12 is an oblique view illustrating a bending part of the load beam;

FIG. 13 is a plane view of a suspension used in a further embodimentaccording to the present invention;

FIG. 14 is a plane view illustrating in detail a flexure used in theembodiment shown in FIG. 13;

FIG. 15 is a plane view of a suspension used in a still furtherembodiment according to the present invention;

FIG. 16 is an oblique view schematically illustrating a part of amagnetic disk drive apparatus in an another embodiment according to thepresent invention;

FIG. 17 is a plane view of the suspension used in the embodiment shownin FIG. 16; and

FIG. 18 is a side view schematically illustrating a connection structurebetween a connection conductor of a flexure shown in FIG. 17 and aconnection cable of the FPC.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, which schematically illustrates a part of a magnetic diskdrive apparatus in a preferred embodiment according to the presentinvention, reference numeral 10 denotes a plurality of magnetic disksrotating around an axis 11, and 12 denotes an assembly carriage devicefor positioning a magnetic head slider on a track of the disk. Theassembly carriage device 12 is mainly constituted by a carriage 14rotatable around an axis 13 and an actuator 15 such as for example avoice coil motor (VCM) for driving the carriage 14 to rotate.

Base portions at one ends of a plurality of drive arms 16 are attachedto the carriage 14, and a plurality of suspensions 17 are mounted on topportions at the other ends of the arms 16, respectively. A magnetic headslider 18 is fixed to a top end portion of each of the suspensions 17.

A slider-suspension assembly constituted by the suspension 17 and themagnetic head slider 18 fixed to the suspension 17 is attached to thetop end portion of the each drive arm 16 so that each of the magnetichead slider 18 opposes to the each surface of the magnetic disks 10.Only one slider-suspension assembly is attached to each of the top andbottom drive arms 16, whereas two slider-suspension assemblies areattached to each of the drive arms 16 between the adjacent magneticdisks.

Branched top portions at one end of a connection cable formed by aflexible printed circuit (FPC) 19 which is connected at the other endthereof to an integrated circuit element for recording and reproducingsignals (not shown) are positioned near the top end portions of therespective drive arms 16 of the carriage 14.

FIG. 2 shows the suspension 17 of the embodiment shown in FIG. 1. In thefigure, reference numeral 20 denotes the resilient flexure forsupporting, by means of its tongue 20a formed near one end of theflexure 20, the magnetic head slider 18 (FIG. 1), 21 denotes the loadbeam for supporting and fixing the flexure 20, and 22 denotes a baseplate fixed to a base end portion of the load beam 21. The other end ofthe flexure 20 is positioned in this embodiment at the side of a frontedge (edge on the slider side) of the base plate 22.

The flexure 20 is made of in this embodiment a stainless steel plate(for example SUS304TA) with a thickness of about 25 μm. If the flexureis made of a plastic material, a poor flatness of the surface to whichthe slider is mounted and/or large angle variations between the slidermounting surface and the surface to which the drive arm is attached mayoccur. However, according to this embodiment, since the flexure 20 isformed by the stainless steel plate, there will occur no such troubles.

As for lead lines, four connection conductors 23-26 of thin filmconductive pattern are formed on the flexure 20 along its whole length.Near the both ends of the flexure 20, connection terminals 23a-26a whichare to be directly connected to the magnetic head slider 18 (FIG. 1) andconnection terminals 23b-26b which are to be directly connected to theconnection cable of the FPC 19 (FIG. 1) are formed on the flexure 20,respectively. These connection terminals 23a-26a and 23b-26b areelectrically connected with each other by means of the connectionconductors 23-26, respectively.

The thin film conductive pattern can be formed by a well known methodsimilar to the patterning method of forming a printed circuit board on athin metal plate. Namely, the conductive pattern are formed bysequentially depositing a polyimide layer with a thickness of about 5 μm(lower insulating material layer), a patterned Cu layer with a thicknessof about 4 μm (conductive material layer), and a polyimide layer with athickness of about 5 μm (upper insulating material layer) on the flexure20 in this order. Within the regions of the connection terminals 23a-26aand 23b-26b, a Ni layer and an Au layer are sequentially deposited onthe Cu layer and there is no upper insulating material layer. In orderto easily understand the structure, the connection conductors 23-26 areindicated by solid lines in FIG. 2.

The load beam 21 is made of in this embodiment a stainless steel platewith a thickness of about 62-76 μm and supports the flexure 20 along itswhole length. Fixing of the flexure 20 to the load beam 21 is achievedby means of means of a plurality of welded spots 27. In this embodiment,this load beam 21 has a terminal support part 21a protruded from theside edge of the base plate 22. On the terminal support part 21a, theother end portion of the flexure 20 with the connection terminals23b-26b is fixed.

The base plate 22 is made of a stainless steel or iron and is fixed tothe base end portion of the load beam 21 by means of welded spots 28.The suspension 17 is attached to the top end portion of the drive arm 16(FIG. 1) by fixing the base plate 22 thereto. In a modification, thebase end portion of the load beam 21 may be constructed to function as abase plate instead of preparing and attaching the individual base plate22.

FIG. 3 illustrates an example of connection structure between theconnection terminals 23a-26a near the top end of the flexure 20 andsignal terminals of the magnetic head slider 18.

In this example, the magnetic head slider 18 has four signal terminals30-33 and the air bearing surface with an area of about 1.25 mm². Aswill be apparent from this figure, the signal terminals 30-33 of theslider 18 are connected with the connection terminals 23a-26a formednear the top end of the flexure 20 by ball bonding of Au, respectively.

Hereinafter, the connection structure between the connection conductors23-26 of the flexure 20 in this embodiment and the connection cable ofthe FPC 19 will be described with reference to FIGS. 4 to 6. FIG. 4schematically illustrates the assembly carriage device 12, FIG. 5illustrates the FPC 19 and FIG. 6 illustrates the connection structureof a single suspension with the FPC connection cable 19.

The connection terminals 23b-26b electrically connected to the otherends of the respective connection conductors 23-26 of each suspension 17are positioned near the side edge of the base plate 22, in other wordspositioned at the top end portion of the drive arm 17 when thesuspension 17 is attached to this drive arm 16. As mentioned before, thebranched top portions at one end of the connection cable of FPC 19 whichis connected at the other end thereof to an integrated circuit elementfor recording and reproducing signals are positioned near the top endsof the respective drive arms 16. Each of the branched top portions ofthe connection cable has cable terminals 34-37 which are connected tothe connection cable.

Therefore, electrical connection of the lead lines of the eachslider-suspension assembly can be completed only by directly connecting,by means of soldering for example, the connection terminals 23b-26b ofthe flexure 20 with the cable terminals 34-37 of the FPC 19 at the topend position of the drive arm 16.

According to this embodiment, as described above, the connectionterminals 23b-26b coupled to the other ends of the respective connectionconductors 23-26 can be directly connected, without using lead wires, tothe cable terminals 34-37 of the FPC connection cable. The other end ofthe connection cable is connected to the electronic circuit forrecording and reproducing signals. As a result, the connection of thelead lines will not affect the flying characteristics of the slider,particularly motion of the slider for roll, and an electrical resistanceof the lead lines can be decreased. This is extremely advantageous for amagnetic head slider with a very small size, and also for a magnetichead slider with a large number of lead lines.

FIG. 7 illustrates measured flying characteristics of theslider-suspension assembly in this embodiment and of the conventionalslider-suspension assembly using wires as for the lead lines. In FIG. 7,(average value), (average value+3σ) and (average value-3σ) of the flyingheight versus position of the slider along the disk radius, with respectto the assembly of this embodiment and to the conventional assembly areillustrated. Solid lines of (average value+3σ) and (average value -3σ)correspond to the assembly of this embodiment, and broken lines of(average value+3σ) and (average value-3σ) correspond to the conventionalassembly. Also, σ indicates a standard deviation. These. flyingcharacteristics were measured for 100 samples under the condition of adisk speed of 7200 rpm.

As will be apparent from this figure, the range between (averagevalue+3σ) and (average value-3σ) of the assembly of this embodiment isnarrower than that of the conventional assembly by about 30%. Thisrepresents that the flying height deviation characteristics is extremelyimproved in this embodiment.

Also, according to this embodiment, since the electrical connection ofthe lead lines can be completed only by directly connecting, by means ofsoldering for example, the connection terminals 23b-26b with the cableterminals 34-37 at the top end position of the drive arm 16, theconnection work of the lead lines with the external circuit can be veryeasily executed and may be automatically executed by a connectionmachine. As a result, the manufacturing cost with respect to theconnection can be reduced.

Furthermore, since the flexure 20 is attached to the load beam 21 alongthe whole length of the load beam, a good damper effect can be expected.In fact, the result of measured vibration characteristics of theslider-suspension assembly of this embodiment and of the conventionalslider-suspension assembly exhibited an increased damper effect in theassembly of this embodiment. Namely, a gain in the second torsion modewas 6 dB in the conventional assembly, whereas 2 dB in the assembly ofthis embodiment.

FIG. 8 illustrates a suspension used in an another embodiment accordingto the present invention.

In the figure, reference numeral 80 denotes a resilient flexure forsupporting, by means of its tongue 80a formed near one end of theflexure 80, a magnetic head slider similar to that shown in FIG. 1, 81denotes a load beam for supporting and fixing the flexure 80, and 82denotes a base plate fixed to a base end portion of the load beam 81.

FIGS. 9a to 9c show sectional views along the A--A line shown in FIG. 8.As shown in these figures, the load beam 81 has a terminal support part81a which is protruded from the side edge of the base plate 82 and isbent to an angle of about 90° with respect to the surface of the baseplate 82. On the terminal support part 81a, the other end of the flexure80 on which a second connection terminal part (90) is positioned isfixed.

The terminal support part 81a may be perpendicularly bent with respectto the load beam 81 in a direction of the base plate 82 as shown inFIGS. 9c and 9d, or in the opposite direction of the base plate 82 asshown in FIGS. 9a and 9b. The other end portion of the flexure 80 isfixed on the terminal support part 81a so that the second connectionterminal part (90) is outward appeared with respect to the base plate82. It is desired that the terminal support part 81a has a shorterlength in the protruding direction as shown in FIGS. 9b and 9d, so thatthe upward and downward protruding length of this support part can beshortened. Although the terminal support part 81a is bent to an angle ofabout 90° in this embodiment, this bending angle may be adaptivelydecided on condition that the connection work with the external circuitcan be easily executed. Smaller bending angle is advantageous becausethe protruding length of the terminal support part 81a will bedecreased.

The flexure 80 is made of in this embodiment a stainless steel plate(for example SUS304TA) with a thickness of about 25 μm. FIG. 10illustrates in detail the structure of this flexure 80. As will beunderstood from this figure, on the flexure 80, four connectionconductors 83-86 of thin film conductive pattern are formed along itswhole length, as for lead lines. Near one end of the flexure 80, a firstconnection terminal part 89 consisting of connection terminals 83a-86awhich are to be directly connected to the magnetic head slider is formedon the flexure 80 in a configuration of the thin film conductivepattern. Near the other of the flexure 80, the second connectionterminal part 90 consisting of connection terminals 83b-86b which are tobe directly connected to the connection cable of FPC similar to the FPC19 shown in FIG. 1 is formed on the flexure 80 in a configuration of thethin film conductive pattern. These connection terminals 83a-86a and83b-86b are electrically connected with each other by means of theconnection conductors 83-86, respectively.

The thin film conductive pattern can be formed by a well known methodsimilar to the patterning method of forming a printed circuit board on athin metal plate. Namely, the conductive pattern are formed bysequentially depositing a polyimide layer with a thickness of about 5 μm(lower insulating material layer), a patterned Cu layer with a thicknessof about 4 μm (conductive material layer), and a polyimide layer with athickness of about 5 μm (upper insulating material layer) on the flexure80 in this order. Within the regions of the connection terminals 83a-86aand 83b-86b, a Ni layer and an Au layer are sequentially deposited onthe Cu layer and there is no upper insulating material layer. In orderto easily understand the structure, the connection conductors 83-86 areindicated by solid lines in FIGS. 8 and 10.

The load beam 81 is made of in this embodiment a stainless steel platewith a thickness of about 62-76 μm and supports the flexure 80 along itswhole length by fixing it at a plurality of points. As mentioned above,this load beam 81 has the terminal support part 81a protruded from theside edge of the base plate 82 and bent to an angle of about 90° withrespect to the surface of the base plate 82. On the terminal supportpart 81a, the other end portion of the flexure 80 on which the secondconnection terminal part 90 is positioned is fixed so that this secondconnection terminal part 90 is outward appeared with respect to the baseplate 82.

Fixing of the flexure 80 to the load beam 81 is achieved at a pluralityof welded spots 87 by laser welding for example. Fixing of the other endof the flexure 80 to the terminal support part 81a is also achieved atwelded spots (not shown in FIG. 8) by laser welding for example. Sincethe flexure 80 and the load beam 81 are fixed to each other by means ofthe welded spots, the flexure 80 will have a free movement part 80bwhich can freely move with respect to the load beam 81 at a positionnear the other end of the flexure 80. Therefore, even if the flexure 80is fixed to the load beam 81, excess stress will not be applied to thethin film conductive pattern on the flexure 80 such as the connectionconductors 83-86.

A slit 92 with a certain length may be partially formed along a bendingline 91 for the terminal support part 81a, with which the terminalsupport part 81a is easily bent.

The base plate 82 is made of a stainless steel or iron and is fixed tothe base end portion of the load beam 81 by means of welded spots 88. Ina modification, the base end portion of the load beam 81 may beconstructed to function as a base plate instead of preparing andattaching the individual base plate 82.

Next, a method of manufacturing the suspension in this embodiment willbe described.

First, the flexure 80 with the thin film conductive pattern is formed.This thin film conductive pattern mainly includes the first connectionterminal part 89 which is positioned near one end of the flexure 80 andis to be directly connected to a magnetic head slider, the connectionconductors 83-86 which is electrically connected to the first connectionterminal part 89 at its one end, and the second connection terminal part90 which is positioned near the other end of the flexure 80 and iselectrically connected to the other end of the connection conductors83-86. Before or after the formation of this thin film conductivepattern, the load beam 81 provided with the terminal support part 81aprotruded in a direction of the side of the load beam 81 is formed. Asshown in FIG. 11, the slit 92 with a certain length is partially formedalong the bending line 91 between the load beam 81 and the terminalsupport part 81a. The base plate 82 with a predetermined shape isprepared. The base end portion of the load beam 81 may be substitutedfor the base plate without preparing the individual base plate 82.

Then, the flexure 80 and the base plate 82 are fixed on the load beam 81by spot welding using laser at several points. In this case, the otherend portion of the load beam 81 is spot-welded on the terminal supportpart 81a so that the second connection terminal part 90 on the flexure80 is fixed on this terminal support part 81a of the load beam 81.Thereafter, the terminal support part 81a is bent, along the bendingline 91, to about 90° with respect to the surface of the base plate 82so that the second connection terminal part 90 is outward appeared withrespect to the base plate 82. Although the terminal support part 81a isbent to an angle of about 90° in the above description, this bendingangle may be adaptively decided on condition that the connection workwith the external circuit can be easily executed. It is possible to fixthe flexure 80 to the load beam 81 by spot welding after bending theterminal support part 81a. However, in this case, the angle of the spotwelding is changed for this part causing the work efficiency to lower.

Since the terminal support part 81a is bent after the other end portionof the flexure 80, on which the second connection terminal part 90 isformed, is fixed to the load beam 81, not only a good work efficiencycan be obtained but also the bending angle of the terminal support part81a can be freely determined. Also, since the slit 92 is partiallyformed along the bending line 91, no excess stress will be applied tothe thin film conductive pattern on the flexure 80 such as theconnection conductors 83-86 preventing the electrical characteristicssuch as electrical insulation or electrical resistance characteristicsfrom deteriorating. Of course, the bending work will become easy.

It is possible, as shown In FIG. 12, to simultaneously bent both theterminal support part 81a of the load beam 80 and the flexure 80 afterthe flexure 80 is tightly adhered on the load beam 81. However,according to this method, since the flexure 80 is sharply bent,distortion of the conductive layer and the insulation layer whichconstitute the thin film conductive lead pattern such as the connectionconductors will increase to produce a microscopic destruction in thethin film layer or a crack in the conductive layer causing theelectrical characteristics such as electrical insulation or electricalresistance characteristics to easily deteriorate. Contrary to this,according to this embodiment, the flexure 80 provided with the freemovement part 80b which can freely move with respect to the load beam 81at a position near the other end of this flexure 80 is fixed to the loadbeam 81 by spot welding, and then only the terminal support part 81a isbent to an arbitrary angle. Therefore, even if the terminal support part81a is bent after the fixing of the flexure 80 to the load beam 81,excess stress will not be applied to the thin film conductive pattern onthe flexure 80 such as the connection conductors 83-86 preventing theelectrical characteristics from deteriorating.

According to this embodiment, as described above, the second connectionterminal part 90 of the thin film conductive pattern formed on theflexure 80 is positioned on the terminal support part 81a by attachingthe other end portion of the flexure 80 to this terminal support part81a which is protruded from the side edge of the base plate 82. Thus,the second connection terminal part 90 can be directly connected,without using lead wires, to one end of the FPC connection cable theother end of which is connected to the external circuit such as anelectronic circuit for recording and reproducing signals. As a result,the connection of the lead lines will not affect the flyingcharacteristics of the slider, particularly motion of the slider forroll, and an electrical resistance of the lead lines can be decreased.Also, any breakage of the wires can be prevented from occurring duringconnection works resulting the fraction defective of manufacturing tomaintain without increasing.

Furthermore, since the second connection terminal part 90 is fixed tothe terminal support part 81a which is bent to an arbitrary angle withrespect to the surface of the base plate 82, the connection terminals83b-86b are outward appeared with respect to the base plate 82 resultingthat the connection work with the FPC can be easily done. Also, becausethe position of the connection terminals 83b-86b is settled, theconnection work of the lead lines with the external circuit can beautomatically executed by a connection machine. As a result, themanufacturing cost with respect to the connection can be reduced.Furthermore, since the flexure 80 is attached to the load beam 81 alongthe whole length of the load beam, a good damper effect can be expected.

FIG. 13 shows a suspension of a further embodiment according to thepresent invention.

In the figure, reference numeral 130 denotes the resilient flexure forsupporting, by means of its tongue 130a formed near one end of theflexure 130, a magnetic head slider similar to that shown in FIG. 1, 131denotes the load beam for supporting and fixing the flexure 130, and 132denotes a base plate fixed to a base end portion of the load beam 131.

The load beam 131 has a terminal support part 131a which is protrudedfrom the side edge of the base plate 132 and is bent to an angle ofabout 90° with respect to the surface of the base plate 132. In FIG. 13,however, this terminal support part 131a is illustrated in a statebefore bending. On the terminal support part 131a, the other end of theflexure 130 on which a second connection terminal part (140) ispositioned is fixed. Although the terminal support part 131a is bent toan angle of about 90° in this embodiment, this bending angle may beadaptively decided on condition that the connection work with theexternal circuit can be easily executed. Smaller bending angle isadvantageous because the protruding length of the terminal support part131a will be decreased.

The flexure 130 is made of in this embodiment a stainless steel plate(for example SUS304TA) with a thickness of about 25 μm. FIG. 14illustrates in detail the structure of this flexure 130. As will beunderstood from this figure, on the flexure 130, four connectionconductors 133-136 of thin film conductive pattern are formed along itswhole length, as for lead lines. Near one end of the flexure 130, afirst connection terminal part 139 consisting of connection terminals133a-136a which are to be directly connected to the magnetic head slideris formed on the flexure 130 in a configuration of the thin filmconductive pattern. Near the other of the flexure 130, the secondconnection terminal part 140 consisting of connection terminals133b-136b which are to be directly connected to the connection cable ofFPC similar to the FPC 19 shown in FIG. 1 is formed on the flexure 130in a configuration of the thin film conductive pattern. These connectionterminals 133a-136a and 133b-136b are electrically connected with eachother by means of the connection conductors 133-136, respectively.

The thin film conductive pattern can be formed by a well known methodsimilar to the patterning method of forming a printed circuit board on athin metal plate. Namely, the conductive pattern are formed bysequentially depositing a polyimide layer with a thickness of about 5 μm(lower insulating material layer), a patterned Cu layer with a thicknessof about 4 μm (conductive material layer), and a polyimide layer with athickness of about 5 μm (upper insulating material layer) on the flexure130 in this order. Within the regions of the connection terminals133a-36a and 133b-136b, a Ni layer and an Au layer are sequentiallydeposited on the Cu layer and there is no upper insulating materiallayer. In order to easily understand the structure, the connectionconductors 133-136 are indicated by solid lines in FIGS. 13 and 14.

The load beam 131 is made of in this embodiment a stainless steel platewith a thickness of about 62-76μm and supports the flexure 130 along itswhole length by fixing it at a plurality of points. As mentioned above,this load beam 131 has the terminal support part 131a protruded from theside edge of the base plate 132 and bent to an angle of about 90° withrespect to the surface of the base plate 132. On the terminal supportpart 131a, the other end portion of the flexure 130 on which the secondconnection terminal part 140 is positioned is fixed so that this secondconnection terminal part 140 is outward appeared with respect to thebase plate 132.

Fixing of the flexure 130 to the load beam 131 is achieved at aplurality of welded spots 137 by laser welding for example. Fixing ofthe other end of the flexure 130 to the terminal support part 131a isalso achieved at welded spots 137 by laser welding for example. Sincethe flexure 130 and the load beam 131 are fixed to each other by meansof the welded spots, the flexure 130 will have a free movement part 130bwhich can freely move with respect to the load beam 131 at a positionnear the other end of the flexure 130. Therefore, even if the flexure130 is fixed to the load beam 131, excess stress will not be applied tothe thin film conductive pattern on the flexure 130 such as theconnection conductors 133-136.

In this embodiment, particularly, the free movement part 130b in theflexure 130 has a play 130c curved to provide an anti-twist function.Thanks for the play 130c, the free movement part 130b can more freelymove. As a result, no excess stress is applied to the thin filmconductive pattern on the flexure 130 even if a part of the flexure 130is distorted during the bending. Therefore, it is very advantageous forpreventing the electrical characteristics from deteriorating.

A slit which is not clearly shown in FIG. 1 may be partially formedalong a bending line for the terminal support part 131a, with which theterminal support part 131a is easily bent.

The base plate 132 is made of a stainless steel or iron and is fixed tothe base end portion of the load beam 131 by means of welded spots 138.In a modification, the base end portion of the load beam 131 may beconstructed to function as a base plate instead of preparing andattaching the individual base plate 132.

The structure of the suspension in this embodiment is the same as thatin the embodiment of FIG. 8 except that the curve play 130c is formed inthe flexure 130. Also, functions and advantages in this embodiment arethe same as those in the embodiment of FIG. 8 except that, by formingthe play 130c, no excess stress is applied to the thin film conductivepattern on the flexure 130 even if a part of the flexure 130 isdistorted during the bending and thus the electrical characteristics canbe certainly prevented from deteriorating.

FIG. 15 shows a suspension of a still further embodiment according tothe present invention.

In the figure, reference numeral 150 denotes the resilient flexure forsupporting, by means of its tongue 150a formed near one end of theflexure 150, a magnetic head slider similar to that shown in FIG. 1, 151denotes the load beam for supporting and fixing the flexure 150, and 152denotes a base plate fixed to a base end portion of the load beam 151.

The other ends of both the load beam 151 and the flexure 150 in thisembodiment extend beyond a rear edge (edge on the side opposite to theslider side) of the base plate 152.

The flexure 150 is made of in this embodiment a stainless steel plate(for example SUS304TA) with a thickness of about 25 μm. If the flexureis made of a plastic material, a poor flatness of the surface to whichthe slider is mounted and/or large angle variations between the slidermounting surface and the surface to which the drive arm is attached mayoccur. However, according to this embodiment, since the flexure 150 isformed by the stainless steel plate, there will occur no such troubles.

On the flexure 150, four connection conductors 153-156 of thin filmconductive pattern are formed along its whole length, as for lead lines.Near one end of the flexure 150, connection terminals 153a-156a to bedirectly connected to the magnetic head slider are formed on the flexure150 in a configuration of the thin film conductive pattern. Near theother of the flexure 150, connection terminals 153b-156b to be directlyconnected to the connection cable of FPC similar to the FPC 19 shown inFIG. 1 are formed on the flexure 150 in a configuration of the thin filmconductive pattern. These connection terminals 153a-156a and 153b-156bare electrically connected with each other by means of the connectionconductors 153-156, respectively.

The thin film conductive pattern can be formed by a well known methodsimilar to the patterning method of forming a printed circuit board on athin metal plate. Namely, the conductive pattern are formed bysequentially depositing a polyimide layer with a thickness of about 5 μm(lower insulating material layer), a patterned Cu layer with a thicknessof about 4 μm (conductive material layer), and a polyimide layer with athickness of about 5 μm (upper insulating material layer) on the flexure150 in this order. Within the regions of the connection terminals153a-156a and 153b-156b, a Ni layer and an Au layer are sequentiallydeposited on the Cu layer and there is no upper insulating materiallayer. In order to easily understand the structure, the connectionconductors 153-156 are indicated by solid lines in FIG. 15.

The load beam 151 which extends beyond the base plate 152 is made of inthis embodiment a stainless steel plate with a thickness of about 62-76μm and supports the flexure 150 along its whole length. Fixing of theflexure 150 to the load beam 151 is achieved at a plurality of weldedspots 157 by laser welding for example. This load beam 151 has aterminal support part 151a laterally protruded from its side edge nearthe rear end of the base plate 152. On the terminal support part 151a,the other end portion of the flexure 150 on which the connectionterminals 153b-156b are positioned is fixed.

The base plate 152 is made of a stainless steel or iron and is fixed tothe base end portion of the load beam 151 by means of welded spots 158.Similar to the suspension 17 shown in FIG. 1, the suspension is attachedto the top end portion of the drive arm 16 (FIG. 1) by fixing the baseplate 152 thereto. In a modification, the base end portion of the loadbeam 151 may be constructed to function as a base plate instead ofpreparing and attaching the individual base plate 152.

The connection structure of the connection terminals 153a-156a formednear the top end of the flexure 150 and the signal terminals of themagnetic head slider 18 (FIG. 1), and the connection structure of theconnection terminals 153b-156b formed on the flexure 150 and theconnection cable of the FPC 19 (FIG. 1) in this embodiment is the sameas those in the embodiment of FIG. 1 except that the connectionterminals 153b-156b are positioned in the rear of the base plate 152, inother words the connection terminals 153b-156b lie halfway between theends of the drive arm 16 when the suspension 17 is attached to thisdrive arm 16. Also, functions and advantages in this embodiment are thesame as those in the embodiment of FIG. 1 except that the connectionwork of the connection terminals 153b-156b with the FPC connection cablecan be more easily executed because these connection terminals are morerearward positioned.

FIG. 16 schematically illustrates a part of a magnetic disk driveapparatus in an another embodiment according to the present invention.

In the figure, reference numeral 160 denotes a plurality of magneticdisks rotating around an axis 161, and 162 denotes an assembly carriagedevice for positioning a magnetic head slider on a track of the disk.The assembly carriage device 162 is mainly constituted by a carriage 164rotatable around an axis 163 and an actuator 165 such as for example avoice coil motor (VCM) for driving the carriage 164 to rotate.

Base portions at one ends of a plurality of drive arms 166 are attachedto the carriage 164, and a plurality of suspensions 167 are mounted ontop portions at the other ends of the arms 166, respectively. A magnetichead slider 168 is fixed to a top end portion of each of the suspensions167.

A slider-suspension assembly constituted by the suspension 167 and themagnetic head slider 168 fixed to the suspension 167 is attached to thetop end portion of the each drive arm 166 so that each of the magnetichead slider 168 opposes to the each surface of the magnetic disks 160.Only one slider-suspension assembly is attached to each of the top andbottom drive arms 166, whereas two slider-suspension assemblies areattached to each of the drive arms 166 between the adjacent magneticdisks.

Branched top portions at one end of a connection cable formed by aflexible printed circuit (FPC) 169 which is connected at the other endthereof to an integrated circuit element for recording and reproducingsignals (not shown) are positioned near the top end portions of therespective drive arms 16 of the carriage 164.

FIG. 17 shows the suspension 167 of the embodiment shown in FIG. 16. Inthe figure, reference numeral 170 denotes the resilient flexure forsupporting, by means of its tongue 170a formed near one end of theflexure 170, a magnetic head slider similar to that shown in FIG. 1, 171denotes the load beam for supporting and fixing the flexure 170, and 172denotes a base plate fixed to a base end portion of the load beam 171.

The other end of the flexure 170 in this embodiment extend beyond a rearedge (edge on the side opposite to the slider side) of the base plate172 so as to form a flexible free end which will not fixed to the loadbeam 171.

The flexure 170 is made of in this embodiment a stainless steel plate(for example SUS304TA) with a thickness of about 25 μm. If the flexureis made of a plastic material, a poor flatness of the surface to whichthe slider is mounted and/or large angle variations between the slidermounting surface and the surface to which the drive arm is attached mayoccur. However, according to this embodiment, since the flexure 170 isformed by the stainless steel plate, there will occur no such troubles.

On the flexure 170, four connection conductors 173-176 of thin filmconductive pattern are formed along its whole length, as for lead lines.Near one end of the flexure 170, connection terminals 173a-176a to bedirectly connected to the magnetic head slider are formed on the flexure170 in a configuration of the thin film conductive pattern. Near theother of the flexure 170, connection terminals 173b-176b to be directlyconnected to the connection cable of FPC similar to the FPC 169 shown inFIG. 16 are formed on the flexure 170 in a configuration of the thinfilm conductive pattern. These connection terminals 173a-176a and173b-176b are electrically connected with each other by means of theconnection conductors 173-176, respectively.

The thin film conductive pattern can be formed by a well known methodsimilar to the patterning method of forming a printed circuit board on athin metal plate. Namely, the conductive pattern are formed bysequentially depositing a polyimide layer with a thickness of about 5 μm(lower insulating material layer), a patterned Cu layer with a thicknessof about 4μm (conductive material layer), and a polyimide layer with athickness of about 5 μm (upper insulating material layer) on the flexure170 in this order. Within the regions of the connection terminals173a-176a and 173b-176b, a Ni layer and an Au layer are sequentiallydeposited on the Cu layer and there is no upper insulating materiallayer. In order to easily understand the structure, the connectionconductors 173-176 are indicated by solid lines in FIG. 17.

The load beam 171 which extends beyond the base plate 172 is made of inthis embodiment a stainless steel plate with a thickness of about 62-76μm and supports the flexure 170 along its whole length. Fixing of theflexure 170 to the load beam 171 is achieved at a plurality of weldedspots 177 by laser welding for example. In this embodiment, a part ofthe flexure 170 extends beyond the rear end of the load beam 171 so thatthe rear end of the flexure 170 and the connection terminals 173b-176bconstitute the free end.

The base plate 172 is made of a stainless steel or iron and is fixed tothe base end portion of the load beam 171 by means of welded spots 178.Similar to the suspension 167 shown in FIG. 16, the suspension isattached to the top end portion of the drive arm 166 (FIG. 16) by fixingthe base plate 172 thereto. In a modification, the base end portion ofthe load beam 171 may be constructed to function as a base plate insteadof preparing and attaching the individual base plate 172.

The connection structure of the connection terminals 173a-176a formednear the top end of the flexure 170 and the signal terminals of themagnetic head slider 168 (FIG. 16) in this embodiment is the same asthat in the embodiment of FIG. 1.

Referring to FIG. 18 which schematically illustrates a connectionstructure between a connection conductor of a flexure shown in FIG. 17and a connection cable of the FPC, the connection structure of theconductors 173-176 and the FPC connection cable 169 (FIG. 16) isdescribed hereinafter.

As will be apparent from FIG. 18, the connection terminals 173b-176bconnected with the other ends of the connection conductors 173-176 ofthe each suspension 167 extend beyond the base plate 172 and position inthe rear of the load beam 171. The branched top portions at one end ofthe FPC 169 which is connected at the other end thereof to an integratedcircuit element for recording and reproducing signals do not extend tothe end of the drive arm 166 but lie halfway on the drive arm 166. Oneach of the branched top portions of the FPC 169, cable terminals184-187 connected with the cable are formed.

Thus, the connection of the lead lines can be completed by directlyconnecting, at the position of the carriage 164, the connectionterminals 173b-176b on the flexure 170 with the cable terminals 184-187of the FPC 169 for each of the slider-suspension assemblies by means ofwelding for example.

Functions and advantages in this embodiment are the same as those in theembodiment of FIG. 1 except that the connection work of the connectionterminals 173b-176b with the FPC connection cable can be more easilyexecuted because these connection terminals are positioned at thecarriage 164 which is more rearward located.

Many widely different embodiments of the present invention may beconstructed without departing from the spirit and scope of the presentinvention. It should be understood that the present invention is notlimited to the specific embodiments described in the specification,except as defined in the appended claims.

What is claimed is:
 1. A method of manufacturing a suspension for amagnetic head slider comprising the steps of:forming a resilient flexurehaving a) a first connection terminal part positioned near one end ofsaid flexure and to be connected to the magnetic head slider, b) asecond connection terminal part positioned near the other end of saidflexure, and c) connection conductors with both ends connectedrespectively with said first and second connection terminal parts, in athin film pattern; forming a load beam having one end portion and aterminal support part protruded from a side edge of said one end portionof said load beam; attaching said flexure on said load beam so that saidsecond connection terminal part is fixed on said terminal support partand so that said flexure has a free movement part near said other end ofthe flexure, said free movement part being capable of freely movingwithout applying excess stress to said thin film pattern of said flexurewhen said load beam is bent; and thereafter bending said terminalsupport part of said load beam by an arbitrary angle so that said secondconnection terminal part faces outwardly at a position of said terminalsupport part.
 2. The method as claimed in claim 1, wherein said loadbeam forming step includes a step of forming a slit for providing lessresistance when said terminal support part is bent.
 3. A method ofmanufacturing a suspension for a magnetic head slider comprising thesteps of:forming a resilient flexure having a) a first connectionterminal part positioned near one end of said flexure and to beconnected to the magnetic head slider, b) a second connection terminalpart positioned near the other end of said flexure, and c) connectionconductors with both ends connected respectively with said first andsecond connection terminal parts, in a thin film pattern; forming a loadbeam having one end portion and a terminal support part protruded from aside edge of said one end portion of said load beam; attaching saidflexure on said load beam so that said second connection terminal partis fixed on said terminal support part and so that said flexure has afree movement part near said other end of the flexure, said freemovement part having a play curved to provide an anti-twist function inorder to freely move without applying excess stress to said thin filmpattern of said flexure when said load beam is bent; and thereafter,bending said terminal support part of said load beam by an arbitraryangle so that said second connection terminal part faces outwardly at aposition of said terminal support part.